The Solution To: Which way is up? A fluid dynamics riddle

PDF Version Also Available for Download.

Description

For flows of the Rayleigh-Taylor type, asymmetries develop in the flow's structure when the density ratio between the two pure fluids is sufficiently different from unity. The flow depicted in the images has a density ratio of three, and consequently an Atwood number (the difference of the densities divided by their sum) of one half. For this Atwood number, the asymmetries are still subtle. The characteristic ''bubble'' and ''spike'' shapes are not prominent, as they are for, say, Atwood numbers of 0.8 (a density ratio of nine) or more. The key to the riddle solution lies with the mixed fluid--the ... continued below

Physical Description

PDF-file: 3 pages; size: 0.2 Mbytes

Creation Information

Miller, P L; Cabot, W H & Cook, A W June 21, 2005.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

For flows of the Rayleigh-Taylor type, asymmetries develop in the flow's structure when the density ratio between the two pure fluids is sufficiently different from unity. The flow depicted in the images has a density ratio of three, and consequently an Atwood number (the difference of the densities divided by their sum) of one half. For this Atwood number, the asymmetries are still subtle. The characteristic ''bubble'' and ''spike'' shapes are not prominent, as they are for, say, Atwood numbers of 0.8 (a density ratio of nine) or more. The key to the riddle solution lies with the mixed fluid--the grayish regions within the plumes. The Probability Density Function, or PDF, of the fluid composition is not symmetric for these conditions. Rather, the PDF is skewed, leaning toward the low-density compositions, corresponding to the predominant mixed compositions containing a greater proportion of light fluid. For a color scale with white representing the lighter fluid and black representing the heavier fluid, this implies that the mixed fluid should appear lighter than with the color scale reversed. Note that the gray plumes of mixed fluid in both frames are not the same shade of gray; the plumes in the bottom frame are lighter than those in the top frame. From the discussion above, this indicates that the lower frame is correctly oriented while the upper frame is upside down.

Physical Description

PDF-file: 3 pages; size: 0.2 Mbytes

Source

  • Journal Name: Physics of Fluids; Journal Volume: 17; Journal Issue: 9

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: UCRL-JRNL-213145
  • Grant Number: W-7405-ENG-48
  • Office of Scientific & Technical Information Report Number: 877922
  • Archival Resource Key: ark:/67531/metadc873511

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • June 21, 2005

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Dec. 1, 2016, 10:57 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 2

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Miller, P L; Cabot, W H & Cook, A W. The Solution To: Which way is up? A fluid dynamics riddle, article, June 21, 2005; Livermore, California. (digital.library.unt.edu/ark:/67531/metadc873511/: accessed August 16, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.